The proposed research plan calls for the completion of two major studies. The first study will provide an in-depth analysis of the factors associated with either success (maintenance of abstinence) or failure (relapse) in a group of smokers who have decided to quit smoking on their own, without the assistance of an external treatment program. This group of unaided quitters will be closely monitored over a period of two years, in order to provide information about both the strategies of "survival" employed by the successful ex-smokers, and the determinants of relapse for those who resume the habit. Particular attention will be paid to the motivational and decision-making processes that are associated with the intention to abstain from smoking. The second study will be a prospective treatment outcome study, in which a relapse prevention program will be systematically compared to a traditional smoking cessation program and a minimal-contact control condition. Subjects in all three groups will be assessed using a variety of newly-developed measures designed to evaluate both cognitive and behavioral components associated with smoking and the maintenance of abstinence. The final objective of this research is to develop a detailed treatment manual containing the most effective components discovered in the course of this research program for distribution and use in future smoking treatment programs.